So I had a slight argument with a friend about a board position... He put it on Eidogo but that just confuses me so I put it here since I find this easier! If there are any lines of play I should add or if you have any questions/comments please feel free to make them and I will check them and take them into consideration :) Happy solving!
(;AB[ga]AB[gb]AB[fb]AB[gc]AB[fd]AB[fe]AB[ee]AB[dd]AB[cd]AB[ce]AB[cf]AB[bf]AB[ae]AW[be]AW[bd]AW[cc]AW[ac]AW[dc]AW[ec]AW[ed]AW[fc]AW[eb]C[Black to play and Win the game. The rest of the board is settled and Black is behind by around 10 points.]AP[goproblems]
(;B[bb];W[bc]
(;B[cb]
(;W[ba];B[ab]
(;W[da]
(;B[fa]
(;W[ca];B[ea]C[RIGHT])
(;W[ea];B[ca]C[RIGHT]))
(;B[ea];W[fa]C[There was no reason to start this Ko. White Thanks you! :(])
(;B[ca];W[db]C[You were in too much of a rush! Now white can live. :(])
(;B[db];W[ca]C[3 in a row kills... Not 4 :(])
(;B[aa]C[Dead shapes are your friend! By the way White will now play elsewhere since he is now alive in sente :(]))
(;W[ea]
(;B[ca];W[da];B[fa]C[RIGHT])
(;B[da];W[db])
(;B[db]C[3 in a row kills... Not 4 :( By the way... You let White live in sente!])
(;B[aa];W[db];B[ca];W[da])
(;B[fa];W[ca])))
(;W[ab];B[ba]
(;W[da]
(;B[fa]
(;W[ca];B[ea]C[RIGHT])
(;W[ea];B[ca]C[RIGHT]))
(;B[ca]C[Yes, Dead shape!RIGHT])
(;B[db];W[aa]C[Cries!])
(;B[aa];W[db]C[and then there was... not even a ko threat :(])
(;B[ea];W[fa]LB[di:Threat?]
(;B[di];W[ca]C[Well lets hope you have LOTS of threats now. White just made his group into a ko for seki when he should have died unconditionally!])
(;B[ca]C[Yea but... Why did you play E19? Wrong for wasting moves!])))
(;W[ea]LB[di:Tenuki?]
(;B[di]C[Correct! White just died in Gote!RIGHT])
(;B[da]C[Was this really needed?])
(;B[ca]C[Was this really needed?])
(;B[db];W[ca];B[da];W[aa]C[Okay... That was silly!])
(;B[aa];W[ca];B[da];W[db]C[*insert tears here*]))))
(;B[ba];W[cb]
(;B[ca];W[ea]C[Not even a Ko threat exists here!])
(;B[da];W[ea]C[Still no ko threats!])
(;B[ea];W[da];B[ca];W[fa]C[You found a Ko... But it has 2 flaws! 1) White takes first 2) its ONLY a ko!]))
(;B[ab]
(;W[cb])
(;W[ea]C[This move is a mistake! You can make a Ko now!]
(;B[cb];W[ca];B[ba];W[db];B[da]C[Yep... But you are STILL wrong!])
(;B[ba];W[cb])
(;B[ca];W[cb])
(;B[da];W[ca])))
(;B[ca];W[cb]
(;B[ea];W[ba]
(;B[aa];W[ab])
(;B[da];W[ab]))
(;B[da];W[ea])
(;B[ba];W[ea]C[Not even a Ko threat exists here!]))
(;B[da];W[ea];B[cb];W[ba]C[:(])
(;B[ea];W[ba]
(;B[ab];W[da];B[cb];W[fa]C[There was no reason to start this Ko. White Thanks you! :(])
(;B[cb];W[da]
(;B[ab];W[fa]C[There was no reason to start this Ko. White Thanks you! :(])
(;B[fa];W[ab])
(;B[ca];W[ab];B[aa]C[Ko!]))
(;B[ca];W[cb]
(;B[aa];W[ab])
(;B[da];W[ab]))
(;B[da];W[ab];B[cb];W[db])))
(;B[da];W[ea]
(;B[bb];W[bc];B[cb];W[ba]C[:(])
(;B[cb];W[bb]))
(;B[ea];W[bb]
(;B[ca];W[ba])
(;B[da];W[ca]))
(;B[ca];W[bb]))